1. Field of the Invention
The invention relates generally to the field of multimedia distribution systems. More particularly, this disclosure relates to a multimedia processing system and method for intelligently optimizing multimedia transport channels.
2. Description of the Related Art
Multimedia service providers use communication systems that deliver multiple program channels to subscribers of the respective service. Program channels include content from local television and radio stations, national and regional networks, governments, movie providers and advertisers, among others. Program content is limited only by the imagination of the creator(s). Community antenna television (CATV) and satellite service providers generally offer packaged services, which include a set of program channels that are provided in return for a subscription fee.
Prior art systems for distributing multiple program channels to subscribers use a combination of signal processors, multiplexers and modulators to deliver multiple program channels in a transport channel. A prior art system for broadcasting multimedia signals is illustrated in FIG. 1. The system receives program channel 1 through program channel 108 that are inserted into corresponding MPEG encoders, multiplexers and modulators to generate a transport channel that includes the encoded program information from a subset of the various channels.
In the illustrated embodiment, program 1 is applied to MPEG encoder 11, multiplexer 21 and modulator 31 to provide the first of eight program channels in transport channel 41. Similarly, program 2 is applied to MPEG encoder 12, multiplexer 21 and modulator 31 to provide a second of eight program channels in transport channel 41. Lastly, program 8 is applied to MPEG encoder 18, multiplexer 21 and modulator 31 to provide the eighth of eight program channels in transport channel 41. In addition, program 101 is applied to MPEG encoder 61, multiplexer 71 and modulator 81 to provide the first of eight program channels in transport channel 91. Similarly, program 102 is applied to MPEG encoder 62, multiplexer 71 and modulator 81 to provide a second of eight program channels in transport channel 91. Lastly, program 108 is applied to MPEG encoder 68, multiplexer 71 and modulator 81 to provide the eighth of eight program channels in transport channel 91. Transport channel 91 is carried in a different portion of the RF spectrum than that used to carry transport channel 41.
Using MPEG compression, CATV systems installed today can transmit up to 10 channels of video in the 6 MHz bandwidth of a single analog transport channel. When combined with a 550 MHz overall bandwidth, this allows the possibility of nearly 1,000 program channels on a system.
Each of the prior art program channels is arranged in a transport channel in a numerical sequence in accordance with its assigned slot in a channel lineup. As further illustrated in FIG. 1, program 1 has a 22% likelihood of being tuned or viewed by a subscriber, program 2 has a 1% likelihood of being tuned or viewed by a subscriber and program 8 has a 1% likelihood of being tuned or viewed by a subscriber. Thus, transport channel 41 is carrying at least three program channels with different likelihoods of being tuned or viewed by a subscriber to the service. More importantly, program 102 has an 18% likelihood of being tuned or viewed, program 108 has a 12% likelihood of being tuned or viewed and program 101 has a 3% likelihood of being tuned or viewed. Thus, there is a higher likelihood that a subscriber will select a tuning operation that will require a local tuner to acquire a carrier signal from a different transport channel due to known or predicated viewing habits.
Satellite distribution services include direct broadcast to the viewer, broadcast to local television affiliates for radio-frequency distribution, or broadcast to CATV head ends for distribution across the above-described terrestrial CATV systems. Regardless of the satellite configuration, an uplink signal containing multiplexed program channels is broadcast from a ground station in one portion of the RF spectrum where it is received by a satellite and re-broadcast via a downlink signal in another portion of the RF spectrum.
Subscribers of CATV and satellite services use one or more tuners configured to lock on to the carrier frequency of the transport channel 50 and down-convert the signals to baseband signals. Appropriately configured demodulators demodulate the baseband signals to extract the underlying program content. The multimedia signal demodulated by the demodulators contains a plurality of multiplexed multimedia streams, each containing the program content from a single cable or satellite “channel” (e.g., HBO).
Subscribers experience a delay as they select or tune program channels. The delays are due to multiple factors including tuning time between multiplexed transport channels, demodulation processing, MPEG decoding and in some cases decryption processing of encrypted content.
The placement of program content on a select program channel is generally dictated by service providers and in some cases by content providers with a desire to be located in a specific range of the channel lineup. Some service providers group premium channels in a first range of the channel lineup and content specific program channels such as channels that provide sports programming in another range of the channel lineup.
A subscriber's experience can be adversely affected by such logically arranged channel lineups. For example, a family of viewers that subscribe to a multimedia service may include viewers with disparate but predictable viewing habits. Children may frequently watch offerings from a select group of program content providers that are transported via a first multiplex of program channels. One or more adults in the home may frequently watch offerings from a number of other program content providers that are transported via additional multiplexes of program channels. For these subscribers, the time it takes their tuner to move to a new carrier signal and acquire a select program channel (i.e., the channel change time) when the subscriber's tuner is presently tuned to a carrier signal that delivers a first multiplex of program channels and the subscriber selects a “new” channel that is provided by a different carrier signal that includes a second multiplex of program channels will be longer than if the program channels were delivered via the same multiplex.
Accordingly, it would be desirable to develop systems and methods that overcome these shortcomings in the random or logical arrangement of program channels in a channel lineup.